This invention relates generally to the arming of projectile carried detonators, including but not necessarily limited to detonators utilized to deploy a projectile retarding parachute after launching of the projectile.
Non-spinning projectile ammunition from which a parachute retarder is deployed during flight in order to establish a desired range to the point of impact, employ an explosive train type of detonator. In certain projectiles there is a fuzing system through which firing of the projectile warhead at target impact is achieved under control of an associated safety-arming device. An auxiliary safety-arming device is associated with such projectile in order to arm the detonator explosive train through which the retarder parachute is deployed at a programmed time during flight of the projectile. The auxiliary safety-arming device receives electrical energy from the warhead fuzing system at the appropriate time to effect such retarder deployment. Hopefully, premature ignition of the detonator is thereby avoided as well as the consequences thereof, which include generation of heat and shock waves and premature expulsion of the parachute which is necessarily violent and therefore extremely hazardous to personnel and equipment because of high velocity explosive fragmentation and the momentum of massive components.
Presently available safety-arming systems for projectile detonators of the aforementioned type are mechanically complex and do not meet all of the explosive design safety requirements normally imposed on ordnance fuzes and safety-arming devices. Some of such requirements include (1) physical interruption in the detonator explosive train for deploying the retarder parachute prior to launch of the projectile, (2) preventing retarder deployment until the projectile is at an acceptable distance from its launch tube, (3) arming the detonator in response to propulsion of the projectile only by sensing of two different and independent conditions reflecting such propulsion, (4) avoiding the use of any pre-stored energy through which premature arming of the detonator may be effected and (5) providing facilities for indicating the safe and armed condition of the safety-arming device at all times prior to installation of the projectile in its launch tube.
It is therefore an important object of the present invention to provide a safety-arming system for a detonator carried by a projectile, meeting all of the aforementioned safety criteria requirements.
It is a further object of the present invention to provide a safety-arming system for the projectile detonator of a launched projectile which is less mechanically complex and more cost effective without any compromise of the safety requirements aforementioned.